Study on high temperature superconducting coil for SMES

We have been undertaking studies regarding high temperature superconducting wire application to a coil for superconducting magnetic energy storage (SMES). As a result, we succeeded in developing an SMES coil using Bi₂Sr₂Ca₂Cu₃O silver-sheathed multifilamentary wire. In liquid nitrogen this coil, comprising 10 pancake coils, has an energy storage capacity of 100 J with DC of 34.2 A and can operate without difficulty at a peak triangular current of 34.2 A with 2 Hz, simulating SMES operation. However, 100 J is too small for practical SMES use. To increase this amount, we investigated liquid neon as a coolant, as well as the magnetic and tensile stress dependence of the wire´s critical current density in liquid neon. In addition, we measured the cooling ability and dielectric breakdown voltage of liquid neon